gc: fix a memory leak

Fix a memory leak in code added in 41abfe1 (maintenance: add
pack-refs task, 2021-02-09), we need to call strvec_clear() on the
"struct strvec" that we initialized.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

builtin/gc.c

@@ -168,9 +168,15 @@ struct maintenance_run_opts;
 static int maintenance_task_pack_refs(MAYBE_UNUSED struct maintenance_run_opts *opts)
 {
 	struct strvec pack_refs_cmd = STRVEC_INIT;
+	int ret;
+
 	strvec_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
 
-	return run_command_v_opt(pack_refs_cmd.v, RUN_GIT_CMD);
+	ret = run_command_v_opt(pack_refs_cmd.v, RUN_GIT_CMD);
+
+	strvec_clear(&pack_refs_cmd);
+
+	return ret;
 }
 
 static int too_many_loose_objects(void)